body {
    background-color: silver;
    height: 100%;
     width:100%;
}

line {
    stroke: #428bca;
    stroke-width: .06;
}

.center {
    position: fixed;
    top: 50%;
    left: 50%;
    width: 600px;
    height: 50%;
    -webkit-transform: translateX(-50%) translateY(-50%);
}

body {
    background: #eee;
}

@keyframes mysnow {
    0% {
        bottom: 100%;
        opacity: 0;
    }
    50% {
        opacity: 1;
        transform: rotate(720deg);
    }
    100% {
        transform: rotate(0deg);
        opacity: 0;
        bottom: 0%;
    }
}

.container {
    position: fixed;
}

.pic {
    position: absolute;
    opacity: 0;
    animation: mysnow 5s;
    height: 30px;
}